Engineer interested in nonlinear mechanics and science & maths in general. Also, politics & humour. The animation in my header is a demonstration of Kepler's Second Law of Planetary Motion (CC-BY-SA) -- see https://en.wikipedia.org/wiki/Kepler%27s_laws_of_planetary_motion You can check out others mathematical animations by me by searching for #WxMaxima. Also, you can find my photographs by searching for #D7000. But please note that of course neither of these hashtags is unique to me.